1. Field
One or more embodiments of the present disclosure relate to a scroll compressor, and more particularly, to a scroll compressor having an improved structure in which reliability of a compression portion can be enhanced.
2. Description of the Related Art
A scroll compressor is an apparatus that compresses a refrigerant by a relative movement obtained by combining a fixed scroll and an orbiting scroll each having a wrap in a spiral shape. The scroll compressor has high efficiency compared to a reciprocating compressor or a rotary compressor, has low vibration and noise, and can be made small and light-weight and thus is widely used in a refrigerating cycle device.
The scroll compressor has a compression chamber formed by the fixed scroll accommodated in a sealed container and the orbiting scroll that faces the fixed scroll and orbits. The compression chamber is tapered from an outer circumferential side toward an inner circumferential side of the compression chamber by rotation of the orbiting scroll. The refrigerant is absorbed from the outer circumferential side of the compression chamber, is compressed and is ejected into the sealed container from a central portion of the compression chamber.
Since the refrigerant needs to be gradually compressed by the scroll compressor as the refrigerant gets closer to the inner circumferential side from the outer circumferential side of the compression chamber, the wraps of the orbiting scroll and the fixed scroll need to be designed so that they can closely contact each other at an appropriate position.
In general, the wraps of the orbiting scroll and the fixed scroll of the scroll compressor may have an involute shape that is capable of being designed from a virtual design reference as a basic circle. However, the involute-shaped wraps have a limitation in maintaining high efficiency of a compressor and in making a relatively small compressor. That is, in order to increase a capacity of the scroll compressor, the size of the scroll compressor need to be increased, or heights of the wraps formed on the orbiting scroll and the fixed scroll need to be increased. However, this is contrary to a trend of making a relatively small compressor. Also, when the heights of the wraps formed on the orbiting scroll and the fixed scroll are increased, pressure generated by compressing the refrigerant results in an action point that increases by the increased heights of the wraps. Thus, a whole moment to be applied to the wraps increases, which may cause a decrease in reliability.
In order to solve the problem, the orbiting scroll and the fixed scroll that constitute the scroll compressor may be designed to have algebraic spiral wraps, of which thickness increases from the outer circumferential side toward the inner circumferential side of the compression chamber.
The scroll compressor having the algebraic spiral wraps is designed based on a designer's experience, because it is difficult to set the design reference, such as the basic circle. Thus, ends of the wraps may have a cuspate or cusp shape, which may cause lowering of reliability of the compression chamber and a processing load.